This invention relates to the control of an automatic climate control system (ACCS) for a motor vehicle heating, ventilation and air conditioning (HVAC) apparatus, and more particularly to a method of adapting the automatic climate control to the comfort preferences of different occupants.
In vehicles having an HVAC apparatus regulated by an ACCS, the driver adjusts a set temperature (Tset) on an interface panel for selecting the desired cabin temperature. An ACCS control module responds to Tset, the actual cabin temperature and the ambient air temperature (Tamb) in a pre-programmed way to control the blower speed, air discharge temperature and air delivery mode. Typically, the control is calibrated to supply sufficient HVAC power to sustain a nominal set temperature under nominal ambient conditions. Deviations of the set temperature and/or the ambient temperature from the nominal value change the HVAC power level by increasing or decreasing the discharge air temperature, and possibly increasing the blower speed.
Of course, most HVAC power levels may be achieved with a variety of combinations of blower speed and air discharge temperature, and it is up to the calibration engineer to determine what combination of settings the system will provide. Since low blower speed is considered to be desirable for most occupants, the system is usually calibrated to maintain a relatively low blower speed and to respond to minor variations in Tset and/or Tamb by changing the discharge air temperature. However, the comfort preferences of any given occupant may differ from those of the calibration engineer, and such occupants frequently override the preprogrammed settings, for example by manually raising the blower speed to increase the air discharge velocity and/or changing the selected air delivery mode. In effect, the entire spectrum of occupant comfort preferences may be characterized by a standard bell curve distribution, as graphically depicted in FIG. 1. The curve has been arbitrarily divided into five regions designated by the letters A, B, C, D and E, with region C representing the group of occupants that are generally satisfied with the pre-programmed settings provided by a properly calibrated ACCS. The pre-programmed settings are too cool for occupants represented by regions B and A, who tend to raise Tset, to manually lower the blower speed, and to select a more diffuse air delivery mode. Conversely, the pre-programmed settings are not cool enough for occupants represented by regions D and E, who tend to lower Tset, to manually raise the blower speed, and to select a more direct air delivery mode.
While the manual override controls may allow different occupants to obtain the HVAC settings they desire, it would be preferable if the ACCS had the flexibility to satisfy the preferences of different occupants while continuing to operate in the automatic control mode. To this end, various control strategies have been developed for adaptively adjusting the control of an ACCS based on observed manual overriding of the pre-programmed HVAC settings. See, for example, the U.S. Pat. No. 5,511,724 to Freiberger et al., issued on Apr. 30, 1996, and assigned to the assignee of the present invention. However, many occupants may prefer a faster and more direct way of adapting the automatic control settings to their own preferences, particularly in cases where several different occupants use the vehicle. Accordingly, what is needed is an ACCS that allows vehicle occupants to select automatic control settings that more nearly correspond to their comfort preferences.
The present invention is directed to an improved motor vehicle automatic climate methodology in which an occupant of the vehicle selects one of a number of automatic climate control settings that are calibrated to satisfy the comfort preferences of different types of occupants. In a first embodiment, the occupant selects one of a number of a pre-programmed control setting schedules that provide different HVAC power levels. In a second embodiment, the occupant first selects a desired HVAC power level, and then activates one of a number of control setting combinations that satisfy both the selected HVAC power level and his or her comfort preference.